Not Applicable
Not Applicable
The present invention relates to a thermal transfer printer, and more particularly to a hand held thermal transfer printer having a cavity for receiving a printer cartridge containing labeling media and an ink ribbon.
There are a number of U.S. patents that disclose electronic apparatus for printing indicia on labels, some of these are restricted to hand held units and others that disclose tabletop units. Hand held labeling machines are disclosed, for example, in U.S. Pat. Nos. 4,264,396, Stewart; 4,407,692, Torbeck; 4,473,426, Goodwin et al.; 4,477,305, Hamisch; 4,490,206, Makely; 4,497,683, Hamisch; 4,498,947, Hamisch et al.; 4,511,422, Hamisch et al.; 4,544,434, Mistyurik; 4,556,442, Torbeck; 4,561,048, Hamisch et al.; and 4,680,078, Vanderpool et al. Tabletop units for this general purpose, some of which are portable are described in U.S. Pat. Nos. 4,440,248, Teraoka; 4,501,224, Shibayama; 4,630,538, Cushing; and 4,655,129, With et al.
The electronic machines for printing labels of the type disclosed above all include the same general combination of elements, a print head, means for feeding labeling media to be printed past the print head, a microprocessor, a read only memory programmed with appropriate instructions to operate the microprocessor, a random access memory, a keyboard with letter, number, and function keys for the entry of alphanumeric information and instructions concerning the indicia to be printed, and a visual display such as a LED, LCD unit to assist the operator in using the machine. In a hand held printer, these components may all be enclosed in a single housing.
The labeling media comprises a series of labels that are attached to a carrier strip. The carrier strip is fed through the printer and legends are printed on the labels. The labels are then removed from the carrier and attached to the objects needing identification. As there are many types of label applications, there are many combinations of labels and carrier strips that provide labels of varying sizes, colors and formats.
A particular type of print head employs thermal transfer printing technology. Thermal transfer printing uses a heat generating print head to transfer a pigment, such as wax, carbon black, or the like, from a thermal transfer ribbon to a labeling media. By using digital technology, characters are formed by energizing a sequence of pixels on the print head which in turn melt the wax or other pigment on the ribbon transferring the image to the labeling media.
In a known thermal transfer printer such as a label printer, labeling media is fed by a paper feed roller simultaneously with a platen roller feeding an ink transfer ribbon. While the labeling media driven by the feed roller runs between the print head and the rotating platen roller, the transfer ribbon is passed between the print head and the platen roller by rotating the platen roller. As a result, the labeling media and the transfer ribbon pass together in overlay relationship between the print head and the platen roller.
Loading the above printers with labeling media and an ink ribbon can be difficult and cumbersome. For example, known hand held label printers, such as disclosed in U.S. Pat. No. 5,165,806, include a cartridge containing both labeling media and an ink ribbon. The cartridge is inserted into a cavity formed in the printer body, and interfaces with the printer to print labels. The interface between the cartridge and the printer, however, is complex, and requires more than one step to lock the cartridge into the printer cavity and engage the printer with the cartridge in order to print labels. Accordingly, a need exists for a printer mechanism which provides a simple interface between a printer cartridge and a printer.
The present invention provides a printer mechanism having a receptacle for receiving a printer cartridge therein. A print head is disposed in the receptacle, and a platen roller is rotatable about a roller axis. The platen roller is movable between a printing position in close proximity to the print head for urging labeling media and ink ribbon toward the print head and a nonprinting position in which the roller platen is spaced a distance from said print head to allow the labeling media and ink ribbon to be slipped therebetween. A platen roller gear is coaxial with said platen roller, and is engaged with a drive gear when the platen roller is in the printing position and disengaged from the platen roller gear when the platen roller is in the nonprinting position. A lever is linked to the platen roller, and is movable between a lock position and an unlock position. Movement of the lever from the unlock position to the lock position moves the platen roller from the nonprinting position to the printing position and extends the lever over the receptacle to lock a printer cartridge received therein.
A general objective of the present invention is to provide a printer mechanism with a simple interface between a printer cartridge and the printer mechanism. This objective is accomplished by providing a printer mechanism and method of use which locks the printer cartridge in a receptacle in the printer, moves a roller platen into a printing position to sandwich labeling media and ink ribbon between the platen roller and a print head, and engages a drive gear with a stationary gear which rotatably drives the drive gear to rotate the platen roller, all in a single action of operating a lever.
The foregoing and other objectives and advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention, however, and reference is made therefore to the claims herein for interpreting the scope of the invention.